﻿/* ***** BEGIN LICENSE BLOCK *****
 *   Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Меню форума Vingrad.
 *
 * The Initial Developer of the Original Code is
 * Jefim Borissov.
 * Portions created by the Initial Developer are Copyright (C) 2006
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor (s):
 * Daniel Abramov
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 * 
 * ***** END LICENSE BLOCK ***** */

var newsManager = {
    init: function () {
        this.newsReader = new newsReader ();
    },
    deinit: function () {
        this.newsReader = null;
    }
}


var rssreader = function (url, observer, refreshInterval) {
    this.url = url;
    this.observer = observer;
    var context = this;
    window.setInterval (
      function () {
          context.refreshItems (context);
    } , refreshInterval);
    this.refreshItems (context);
}

rssreader.prototype = {
    refreshItems: function (context) {
        context.observer.beginRefreshItems ();
        xmlhelper.loadAsync (context.url, function (rss) { context.onComplete (rss, context.observer); } , function (xmlReq) {  context.onError (xmlReq, context.observer) });
    },
    onComplete: function (rss, observer) {
        observer.refreshItemsComplete (rss);
    },
    onError: function (xmlReq, observer) {
        observer.refreshItemsError (xmlReq);
    }
}

var newsReader = function () {
    this.element = $ ("vingradmenu-tb-news-container");
    this.loadingElement = $ ("vingradmenu-tb-news-loading");
    var url = settings.getNewsRssUrl ();
    var refreshInterval = settings.getRssRefreshInterval ();
    this.xsl = xmlhelper.load (settings.getRssXslUrl ());
    this.reader = new rssreader (url, this, refreshInterval);
}

newsReader.prototype = {
    itemsCount: 0,

    cleanup: function () {
        if (this.itemsCount > 0) // новости уже там есть
            for (i = 1; i <= this.itemsCount; i++) // удаляем все новости (childNodes[0] - надпись "Загрузка")
                this.element.removeChild ($ ("vingradmenu-tb-news-item-" + i));
        this.itemsCount = 0;
    },
    beginRefreshItems: function () {
        this.cleanup ();
        this.loadingElement.hidden = false;
    },
    refreshItemsComplete: function (rss) {
        var nsResolver = function (prefix) {
            var ns = {
              'rss' : 'http://purl.org/rss/1.0/',
              'rdf' : 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'
            };
            return ns[prefix] || null;
        }
        this.cleanup ();
        this.itemsCount = rss.evaluate("count(/rdf:RDF/rss:channel/rss:items/rdf:Seq/rdf:li)", rss, nsResolver, XPathResult.ANY_TYPE, null).numberValue; 
        if (this.itemsCount > 20) this.itemsCount = 20;     
        this.element.appendChild (xmlhelper.transform (rss, this.xsl));
        this.loadingElement.hidden = true;
    },
    refreshItemsError: function () {
        this.cleanup ();
        this.loadingElement.hidden = false;
        this.loadingElement.label = "Ошибка при получении списка новостей";         
    }
} 
